The invention relates to liquid crystal displays and backlight modules thereof, and in particular to backlight modules utilized in liquid crystal displays.
Backlight modules provide light in liquid crystal displays. As the size of liquid crystal displays increases, the light intensity of the backlight module is required to be higher. As a result, more lamps are used, and power consumption is increased accordingly. Excess heat, however, is produced during operation, increasing the temperature in the area surrounding the lamps. In some circumstances, although the number of the lamps and power supply are increased, the light intensity cannot be efficiently increased because the high temperature therein reduces the light intensity over time.
An aluminum plate is often used to dissipate heat in the backlight module. As shown in FIG. 1, the conventional backlight module 10 comprises a reflective sheet 11, a diffusion sheet 16, optical films 17a, 17b, a plurality of lamps 13 and aluminum back plate 15. The diffusion sheet 16 covers the lamps 13 disposed above the reflective sheet 11. The lamps 13, supported by a lamp holder (not shown), are the light source of the backlight module 10. The reflective sheet 11 is disposed above the aluminum back plate 15, reflecting light from the lamps 13 out of the backlight module 10. The aluminum back plate 15 is disposed at the bottom of the backlight module 10 to dissipate heat.
The reflective sheet is an essential element used to reflect light; hence, the heat is blocked thereby and cannot be directly transmitted to the aluminum back plate. Thus, heat cannot be quickly dissipated, and temperature increases therein, reducing light intensity.